A common problem encountered during highway driving is the visibility obscuring water spray that is generated by trucks, tractor-trailer rigs and other large wheeled vehicles. As the wheeled vehicle moves over a wet surface, the rotation of its wheels generates a water spray of a mist-like consistency that is turbulently discharged from the vehicle in a direction generally transverse to the direction of vehicle movement. In many cases this lateral discharge of spray can so obscure visibility as to make it extremely hazardous to drive past such a vehicle under wet road conditions.